1. Field of the Invention
The present invention relates to a stationary original type image reader which reads image information formed by light beams reflected from an original irradiated by a light source lamp moving over the original and particularly to a housing structure for a carriage fixing screw by which a carriage can be fixed with an external screw.
2. Description of the Related Art
An image reader of stationary original type such as a copying machine, scanner, etc. to read and process an original image e.g. on a piece of paper placed on a platen glass is provided with a carriage to scan the original. This carriage comprises e.g. a light source lamp to illuminate an original, a reflector to form an optical path to pick up a target image on the original and guide it to an image processor such as CCD (Charge Coupled Device), etc. This carriage is moved along the original to scan and pick up an image formed on the original.
The optical path length from an image face to the image processor must be kept at a predetermined length even when the carriage moves. To this effect, it has a combined structure consisting of a full rate carriage moving over a distance covering the whole face of an original and a half rate carriage covering the half of that of the full rate carriage. In other words, the full rate carriage comprises a first reflector to receive incidence of an image of an original, while the half rate carriage comprises a second reflector to receive incidence of an image reflected on the first reflector and a third reflector to receive incidence of an image reflected on the first reflector, whereby an image reflected on the third reflector is incident on an image processor. Then, the full rate and half rate carriages are moved as connected with and pulled by wire wound around a pulley thanks to the power of a motor.
The full rate and half rate carriages are both movable so that they may be moved if externally shocked or vibrated. Continuous shocks, if any, e.g. when being transported, may deviate the angle of each reflector or even damage the carriages if violently moved. Therefore, each carriage is externally fixed with a carriage fixing screw e.g. in the case of transporting an image reader.
This carriage fixing screw is used until the image reader is placed as predetermined for use. Conventionally, this carriage fixing screw used to be removed and collected e.g. by a mover or stored in the vicinity of the image reader, since the image reader is typically not moved, once set at a predetermined place. However, with offices moving more and more often nowadays, inevitably image readers are moved more frequently, necessitating the use of a carriage fixing screw to prevent any unintended movement of the carriage when being moved.
However, a carriage fixing screw, if collected by a mover, can not be used any more, while it may be forgotten or lost after a long period, even if stored in the vicinity of the image reader. Then, the image reader is carried without fixing the carriage, with the risk of damage or deformation due to unintended movement of the carriage. Moreover, the necessity of fixing it with a carriage fixing screw in itself may be forgotten, when carrying the image reader.
An object of the present invention is to provide a housing structure for a carriage fixing screw to prevent missing of a carriage fixing screw, removed from an image reader settled at a predetermined place and not needed until another opportunity of transport and to remind of the necessity of fixing the carriage, when moving the image reader.
As technical means to achieve the above object, a housing structure for a carriage fixing screw according to the present invention is characterized in that a carriage fixing screw is provided for externally screwing and fixing a carriage carrying a light source lamp thereon and a carriage carrying a reflector for guiding a reflected light beams to a light receiving station is held, when not used, by a screw holder formed on a part of an image reader in which a light source lamp moves over an original placed on a platen glass.
A carriage fixing screw removed from an image reader is housed in the above screw holder. As a result, the carriage fixing screw is stored in the image reader in itself. Then, the carriage fixing screw is prevented from being lost. Moreover, the presence of this carriage fixing screw is noticed, when trying to carry again the image reader, to remind of the necessity of fixing the carriage.
A housing structure for a carriage fixing screw according to the present invention is characterized in that the above screw holder comprises a holder to hold the threaded part and a housing to house the head of the above carriage fixing screw. The threaded part of the carriage fixing screw is held, while the head is housed in the above housing to prevent the carriage fixing screw from projecting around the image reader. As a result, the appearance of the image reader is not compromised and the user of the image reader is protected from the risk of being hooked by the carriage fixing screw by mistake.
Moreover, the housing structure for a carriage fixing screw is characterized in that the above screw holder is formed on a back face of the main body of the above image reader. Thus, the carriage fixing screw is invisibly housed when using the image reader as usual. Then, the carriage fixing screw is prevented from being lost without compromising the appearance of the image reader.
This housing structure for a carriage fixing screw is characterized in that the screw holder is formed on a back face of a lid covering the platen glass of the above image reader. When attached to the main body of the device, the threaded part of the carriage fixing screw projects inside of the main body. As a result, it requires a space to place this threaded part, likely to restrict the degree of freedom to arrange the respective parts inside the main body of the device. On the other hand, a screw holder arranged on a lid is hardly detrimental to the degree of freedom to arrange the respective parts, without compromising the appearance of the image reader.